Projectile weapons, specifically small arms have long relied on optical sights to increase the weapons accuracy at range. Telescopic and electronic gun sights provide a user with a magnified field of view that when oriented towards a target's direction facilitates the user's target acquisition and produces more accurate shot placement. To achieve these results, optical sights have to properly calibrate the positioning of the reticle. The reticle is the set of intersecting lines that serve as the crosshairs and positioned within the optical sight in a manner that is viewable to the user when they position their eye on the ocular. Proper positioning of the reticle aligns the sight's crosshairs with the intended point of impact for the projectile. A user would increase or decrease the vertical positioning of the reticle to accurately adjust the crosshairs to coincide with the point of impact for the projectile. At increased distances, a user has to significantly decrease the vertical positioning of the reticle to align the crosshairs with the point of impact due to bullet drop. Although, many optical sights are able to adjust the positioning of their reticle with a distant target, the increased distances create another issue that can result in aiming errors.
Optical sights rely on a moveable reticle that is positioned in front of the ocular, but placed behind the objective lens. When the user peers through an optical sight the reticle images appears superimposed over the magnified image. Due to the reticle and the magnified image not being coplanar to one another, the positioning of the reticle relative to the magnified image, as perceived by the user's eye may be misaligned. This issue is an optical effect known as parallax. Parallax is the displacement or difference of the apparent position of an object viewed along two different lines of sight. Shot placement misalignment caused by parallax, or parallax induced aiming errors as it is commonly known, is well documented and optical sights have developed mechanisms that allow a user to adjust and compensate for the miss alignment of a reticle with a magnified image.
Some of the mechanisms that are currently available to compensate for parallax consist of an integrated parallax compensation mechanism found within the optical sight and specially designed optical sights that eliminate parallax aiming errors within a specified range. The integrated parallax compensation mechanisms are able to effectively compensate for the parallax induced errors by incorporating a moveable optical element that enables the optical system to project the image of the object at varying distances and have the reticle's crosshairs projected on the same optical plane. Another method that is currently available on the market is the use of a permanently calibrated optical sight. These optical sights perform effectively without the compensation for parallax induced error by being permanently calibrated for the distance that best suits their intended use. While both of these solutions are able to reduce parallax induced aiming errors, they suffer from several disadvantages.
One drawback that is seen in adjustable optical sights is that they can only effectively compensate for parallax without adjustment while the intended target is found within a specific distance. While this inconvenience is nearly unavoidable at greater distances, it does require frequent repositioning of the reticle to compensate for parallax. The frequent readjustment of a reticle can result in wear and tear to the intricate mechanisms that are found within the optical sight. These mechanisms are difficult to replace and service if damaged, and most often, a malfunctioning or damaged optical sight requires a complete replacement. Still another disadvantage that is associated with readjustment of the reticle is the inability to verify at what distance the reticle is calibrated for. This disadvantage can be time consuming and frustrating for users to verify and is a nuisance for users who need to quickly readjust the reticle for aiming at a plurality of targets with varying distances. While the permanently calibrated optical sights do not suffer from the wear and tear associated with the frequent readjustment of the reticle, these optical sights suffer from another disadvantage as a result of their design. The permanently calibrated optical sights are unable to effectively compensate for parallax outside their intended range. This obvious limitation can create several situations where the sight is unable to effectively function. While both of these types of optical sights have disadvantages related to their parallax compensation function, they also carry and economic disadvantage. Both of these optical sights are significantly more expensive relative to the price of optical sights that do not include these parallax compensation mechanisms.
Therefore, it is the object of the present invention to resolve the parallax induced error that occurs in optical sights through an apparatus that adjusts the elevational positioning of an optical sight as opposed to requiring the optical device to constantly readjust the positioning of the reticle. This apparatus allows a user to quickly calibrate their optical sights for acquiring targets at varying distances.